Influence of PRKAG2 gene novel mutation on glycogen storage and calcium homeostasis in cardiomyocytes / 第二军医大学学报

ABSTRACT

Objective PRKAG2 G100S is a novel mutation recently found in Chinese patients with PRKAG2 cardiac syndrome. The present study is to investigate the mechanism by which PRKAG2 G100S induces cardiac hypertrophy. Methods The recombinant adenovirus containing human PRKAG2 gene was constructed and used to infect H9c2 cells and neonatal rat cardiomyocytes using EGFP as the reporter gene, and Western blotting analysis was used to determine PRKAG2 protein expression. The intracellular free Ca2+ was determined in H9c2 cells before and 48 h after infected with Ad-EGFP, Ad-PRKAG2 or Ad-PRKAG2 G100S by incubating with Rohd2/AM. The glycogen contents in neonatal rat cardiomyocytes were determined by PAS 48-72 h after infection. Results Bright green fluorescence was observed in the cultured H9c2 cells and neonatal rat cardiomyocytes 48-72 h after infected with Ad-PRKAG2 GlOOSEGFP and Ad-PRKAG2-EGFP. Over-expressed PRKAG2 protein was identified with PRKAG2 monoclonal antibody. Intercellular free Ca2+ concentrations in H9c2 cells were similar among various groups 48-72 h after infection, and the concentrations were not significantly different before and 48 h after infection in each group. PAS revealed more glycogen in the neonatal rat cardiomyocytes in PRKAG2 G100S group 48 h after infection compared with the other two groups. Conclusion Our findings indicate that myocardial glycogenosis might contribute to the pathogenesis of cardiac hypertrophy in patients with PRKAG2 G100S mutation, and the imbalance of calcium homeostasis in cardiomyocytes might not be involved in the pathogenesis.